AD5940 Temperature Example

After looking at page 399 of the ADuCM350 hardware reference manual 

https://www.analog.com/media/en/technical-documentation/user-guides/aducm350_ug-587.pdf

I modified the sequence so that the temperature sensor was powered on and off along with the ADC. 

  //generate sequence to measure temperature sensor output
  AD5940_SEQGenInit(buff, BUFF_SIZE); //init sequence generator
  AD5940_SEQGenCtrl(bTRUE); //from now on, record all register operations rather than write them to AD5940 through SPI.
  AD5940_SEQGpioCtrlS(AGPIO_Pin1);  //pull high AGPIO1 so we know the sequencer is running by observing pin status with oscilloscope etc.
  AD5940_SEQGenInsert(SEQ_WAIT(16*200));  /* Time for reference settling(if ad5940 is just wake up from hibernate mode) */
  AD5940_AFECtrlS(AFECTRL_ADCPWR|AFECTRL_TEMPSPWR, bTRUE); /* Turn ON ADC and temperature sensor power */
  AD5940_SEQGenInsert(SEQ_WAIT(16*50));   /* wait another 50us for ADC to settle. */
  AD5940_AFECtrlS(AFECTRL_TEMPCNV|AFECTRL_ADCCNV|AFECTRL_SINC2NOTCH, bTRUE);  /* Start temperature and ADC convert */
  AD5940_SEQGenInsert(SEQ_WAIT(WaitClks));
  AD5940_AFECtrlS(AFECTRL_TEMPCNV|AFECTRL_ADCCNV|AFECTRL_SINC2NOTCH, bFALSE);    /* Stop ADC convert, hw ref manual p. 53 says TEMOCNV resets to 0 after conversion */
  AD5940_AFECtrlS(AFECTRL_ADCPWR|AFECTRL_TEMPSPWR, bFALSE); /* Turn off ADC and temperature sensor power */
  AD5940_SEQGenInsert(SEQ_WAIT(20));			/* Add some delay before put AD5940 to hibernate, needs some clock to move data to FIFO. */
  AD5940_SEQGpioCtrlS(0);     /* pull low AGPIO so we know end of sequence.*/
  AD5940_EnterSleepS();/* Goto hibernate */
  AD5940_SEQGenCtrl(bFALSE);  /* stop sequence generator */
  if(AD5940_SEQGenFetchSeq(&pSeqCmd, &seq_len) != AD5940ERR_OK){

I'm now getting reasonable values 

Gain: 0x00004000
Offset: 0x00000000
Result[0] = 3622, 23.86(C)
Result[1] = 3622, 23.86(C)
Result[2] = 3623, 23.94(C)
Result[3] = 3622, 23.86(C)

These increase and decrease as I warm and cool the IC

After looking at page 399 of the ADuCM350 hardware reference manual 

https://www.analog.com/media/en/technical-documentation/user-guides/aducm350_ug-587.pdf

I modified the sequence so that the temperature sensor was powered on and off along with the ADC. 

  //generate sequence to measure temperature sensor output
  AD5940_SEQGenInit(buff, BUFF_SIZE); //init sequence generator
  AD5940_SEQGenCtrl(bTRUE); //from now on, record all register operations rather than write them to AD5940 through SPI.
  AD5940_SEQGpioCtrlS(AGPIO_Pin1);  //pull high AGPIO1 so we know the sequencer is running by observing pin status with oscilloscope etc.
  AD5940_SEQGenInsert(SEQ_WAIT(16*200));  /* Time for reference settling(if ad5940 is just wake up from hibernate mode) */
  AD5940_AFECtrlS(AFECTRL_ADCPWR|AFECTRL_TEMPSPWR, bTRUE); /* Turn ON ADC and temperature sensor power */
  AD5940_SEQGenInsert(SEQ_WAIT(16*50));   /* wait another 50us for ADC to settle. */
  AD5940_AFECtrlS(AFECTRL_TEMPCNV|AFECTRL_ADCCNV|AFECTRL_SINC2NOTCH, bTRUE);  /* Start temperature and ADC convert */
  AD5940_SEQGenInsert(SEQ_WAIT(WaitClks));
  AD5940_AFECtrlS(AFECTRL_TEMPCNV|AFECTRL_ADCCNV|AFECTRL_SINC2NOTCH, bFALSE);    /* Stop ADC convert, hw ref manual p. 53 says TEMOCNV resets to 0 after conversion */
  AD5940_AFECtrlS(AFECTRL_ADCPWR|AFECTRL_TEMPSPWR, bFALSE); /* Turn off ADC and temperature sensor power */
  AD5940_SEQGenInsert(SEQ_WAIT(20));			/* Add some delay before put AD5940 to hibernate, needs some clock to move data to FIFO. */
  AD5940_SEQGpioCtrlS(0);     /* pull low AGPIO so we know end of sequence.*/
  AD5940_EnterSleepS();/* Goto hibernate */
  AD5940_SEQGenCtrl(bFALSE);  /* stop sequence generator */
  if(AD5940_SEQGenFetchSeq(&pSeqCmd, &seq_len) != AD5940ERR_OK){

I'm now getting reasonable values 

Gain: 0x00004000
Offset: 0x00000000
Result[0] = 3622, 23.86(C)
Result[1] = 3622, 23.86(C)
Result[2] = 3623, 23.94(C)
Result[3] = 3622, 23.86(C)

These increase and decrease as I warm and cool the IC

NormS 

At what point do you read the Temperature Value? I would like to poll the temperature data.